Levity at the expense of another person’s feelings is still bullying. Especially when that levity depreciates the value of those feelings.
When levity is generated with the full understanding that someone else is hurting, then the levity is grossly inappropriate and unkind. Levity created in a vacuum of unawareness may be less inappropriate and less unkind, but it’s not less hurtful.
We may not always avoid hurting others, but should we not at least try to limit doing harm?
In our imperfect state, we all make mistakes and we all find ourselves guilty of less-than-kind behavior or speech, but we do not need to revel in our imperfection.